KR20090082106A - Oil-based mold release agent for casting, coating method and electrostatic coating apparatus - Google Patents

Abstract

Disclosed is an oil-based mold release agent for casting, which is characterized by containing 0-7.5% by mass of one or more kinds of water selected from the group consisting of distilled water, ion-exchanged water, tap water, and water obtained by dissolving an electrolyte into one of the preceding waters, and 0.3-30% by mass of a solubilizer. Also disclosed are a method for coating such a mold release agent and an electrostatic coating apparatus for such a mold release agent.

Description

OIL-BASED MOLD RELEASE AGENT FOR CASTING, COATING METHOD AND ELECTROSTATIC COATING APPARATUS}

The present invention relates to an oil-based mold release agent for casting used in the casting of nonferrous metals such as aluminum, magnesium and zinc, a coating method using the release agent and an electrostatic coating device.

As is well known, over the past 40 years, more than 99% of the release agents used in the casting of nonferrous metals such as aluminum, magnesium and zinc have been water-soluble release agents. Three years ago, oil-based mold release agents have been used that allow casting by 1/500 to 1/1000 and a small amount of coating compared to the amount of water-soluble. However, the oil-based mold release agent sometimes has insufficient formation of an oil film in a mold having a complicated structure or a large mold for a small amount of coating. In the case of a mold having a complicated structure, oil film formation is particularly insufficient at the mold site covered from the coated surface. In addition, since there are irregularities in the mold, a release film is formed thickly in the recess.

On the other hand, a thin release film tends to be formed in the convex portion. Therefore, excessive release agent accumulates excessively in the concave portion, which causes an increase in the address, and convex portion is likely to cause welding due to lack of release property. As a countermeasure, it is a reality that the amount of coating of the brothers is increased and cast so that a large amount of spray particles are also injected into the masked portion or the convex portion at the expense of a slight increase in address. Moreover, in the case of a large metal mold | die, the thermal energy which the molten nonferrous metal has is large. Therefore, the temperature of the whole metal mold | die, especially a thin site | part may become high temperature 350 degreeC or more near to the temperature of a molten metal.

As a result, the oil-based mold release agent causes Leidenfrost phenomenon and the droplets of the mold release agent boil. In addition, droplets scattered from the mold surface to the bottom due to boiling also increase. Therefore, the oil film formed may become thin and releasability may fall. As a response, two kinds of methods are taken. One is to apply a lot in order to thicken the oil film. The other is to apply a small amount of water to a thin hot spot and apply an oily release agent after cooling. If a lot of release agents are applied, the oil film thickness at the site where a sufficient oil film is formed also increases. As a result, the amount of addresses in the castings tends to increase. Moreover, the strength of a cast product may fall slightly. In addition, piping for applying even a small amount of water is required.

As described above, according to the prior art, there have been the following problems. That is, a mold release agent is not fully supplied to the covered part of a metal mold | die, and an oil film suitable for mold release cannot be formed in that part. In addition, a uniform oil film cannot be formed at the uneven portion of the mold, and the mold release agent must be excessively applied. In addition, it is not possible to form a sufficient oil film in the thin portion of the mold.

For this reason, various improvement techniques have conventionally been proposed.

Japanese Patent Application Laid-open No. Hei 6-182519 (Patent Document 1) discloses a negative charge of a release agent oil drop in an application device to be sprayed into a mold of positive charge, so that the sprayed release agent oil drop reaches a hidden portion of the mold. It's about technology. However, in this technique, the conductivity of the water-soluble releasing agent is so good that the conductivity is not degraded even if the water is slightly reduced. Therefore, electrostatic coating cannot be applied to a water-soluble mold release agent. In addition, the oil-based release agent is too good in insulation, and is not suitable for electrostatic coating.

Japanese Patent Application Laid-Open No. 2001-259787 is the same as Patent Document 1, and relates to a water-soluble type technology containing a large amount of silicon. However, this technique is difficult to apply to oily release agents.

Japanese Patent Application Laid-open No. Hei 9-235496 relates to a technique for lowering the electric resistance value by adding alcohol or ammonium salt as an electrostatic aid as a means of imparting conductivity to the paint. Japanese Patent Application Laid-Open No. 2000-153217 relates to a technique suggested to add an electrostatic aid to paint. However, the "polarity electrostatic aid" in the "low polarity oil releasing agent" melts only about 0.3% by weight, causing sedimentation and separation. As a result of the present applicant's examination, the effect of increasing the deposition amount of the electrostatic preparation was not seen at this level. Adding polar solvents increases the dissolution of the electrostatic aid, but tends to impair the health of the casting operator for polar solvents. Therefore, a polar solvent is not used for the composition of an oil-based mold release agent in consideration for health.

In addition, Japanese Patent Application Laid-Open No. 61-42462, which discloses a technique of electrostatic coating of a high temperature mold release agent and a low temperature mold release agent, is disclosed, and Japanese Patent Application Laid-Open No. 61-182519, which discloses a technique relating to ultrasonic waves, is known. .

The present invention provides an oil-based mold release agent for casting, a coating method, and an electrostatic coating device capable of forming a sufficient oil film on a masked part, a convex part, or a thin part of the mold without excessively applying the oil type release agent to the recessed part. The purpose.

1) In order to achieve the above object, the oil-based release agent for casting of the present invention (first invention) is characterized by containing the following (a), (b).

(a) 0 to 7.5% by mass of distilled water, ion-exchanged water, tap water, or water composed of one or two or more selected from the group of water in which an electrolyte is dissolved in those waters;

(b) 0.3 to 30 mass% of solubilizer

2) The coating method of the present invention (second invention) is characterized by electrostatic coating using the oil-based release agent according to the above 1).

3) The present invention (third invention) is characterized in that an electrostatic coating gun is provided on the electrostatic imparting device and the multi-axis robot for electrostatic coating according to 2) above.

According to the present invention, it is possible to form a sufficient oil film even on the hidden part, uneven part or thin part of the mold without excessive application of the oil type release agent. In fact, the application of the "composition of a solubilizer in which water is dissolved into an oil-based release agent" is applied by the electrostatic coating device of the present invention, and the adhesion of the release agent component to the mold is greatly increased. In particular, when an electrostatic coating gun is provided on a multi-axis robot capable of electrically controlling movement, the effect of electrostatic provision is amplified.

Brief Description of Drawings [Fig. 1] Fig. 1 is a schematic overall schematic view of an electrostatic coating device according to a first embodiment of the present invention.

FIG. 2 is an explanatory view showing an enlarged portion of the electrostatic coating device of FIG.

3 is a measuring apparatus for measuring the adhesion amount of an oil-based release agent to a metal mold | die.

It is explanatory drawing of the state which apply | coats a mold release agent with a coating nozzle to the iron plate for friction measurement.

4B is an explanatory diagram for measuring the frictional force of the solidified aluminum in the ring while pulling in one direction the ring loaded through the friction measuring iron plate on the tester mount.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The above-mentioned conventional oil-based mold release agent is formed from a solvent or base oil of petroleum-based saturated hydrocarbon which does not contain water and has a low polarity. As an additive of an oil-based mold release agent, it contains lubricating additives, such as silicone and vegetable oil, and high viscosity petroleum hydrocarbon oil for oil film maintenance. For example, what was described by reference PCT / JP2005 / 015737, and the mold release agent conventionally called "granular agent" is mentioned.

Such an oil-based release agent is said to be unsuitable for electrostatic coating because its electric resistance value is infinite. In the paint industry, there is an empirical value that the electrostatic coating is easy when the electric resistance value is in the range of 5 to 50 MΩ. For example, if 0.8% by weight of water is dissolved in an oil releasing agent with the aid of a solubilizer, the electrical resistance value is lowered to about 20 MΩ. In the present invention, as described above, one or two or more kinds of water selected from the group of (a) distilled water, (b) ion-exchanged water, (c) tap water, and (d) tap water with a small amount of electrolyte mixed with water are 0. To 7.5 mass% is added as an essential requirement. This reason is as follows.

That is, when water exceeds 7.5 mass%, water will separate from an oil-based mold release agent, an electric resistance value may increase, or it may become infinite depending on the grade of separation. For this reason, 7.5 mass% of water was made into the upper limit of this invention. On the other hand, when the moisture content is 0% by mass, the needle of the electric resistance meter hardly reacts, and the resistance value becomes infinite.

The present inventors electrostatically applied the oil-based mold release agent to a level close to infinity exceeding 50 MΩ, which is the upper limit of the electric resistance experienced in the coating industry. As a result, as will be described later, an increase in adhesion amount due to the electrostatic effect is observed. This is for the following reason. In general, while the electric resistance value is measured at 1.5 volts of a battery in a beaker, the voltage at the time of power failure in the adhesion test is applied at 60 kPa and 40,000 times the intensity. Therefore, even if the resistance value in the beaker is close to infinity, it is estimated that the electrostatic effect appeared in the actual electrostatic coating gun. In other words, the electrical resistance range required for the release agent is considerably wider than the experience in the paint industry.

In the present invention, the water in each of the above-mentioned (a), (b), (c), and (d), in this order, improves the responsiveness at the time of measuring the electrical resistance of water. However, it hardly affects the amount of moisture for setting the electric resistance value required for electrostatic coating. In other words, when the electrolyte is dissolved, the response speed is increased, but the amount of water required for reducing the electrical resistance hardly changes. In addition, when an electrolyte such as potassium hydroxide is mixed, there is a possibility that the emulsification of the mold release agent itself may be promoted, and the solubilizer may be thickened as an emulsifier. In view of responsiveness and emulsification, tap water was used in Examples described later, but water quality is not particularly limited.

In the present invention, in order to dissolve or solubilize water, solvents of alcohols, glycols, esters, ethers, ketones, and emulsifiers can be considered. However, if a solvent in which water is dissolved is also not dissolved in the petroleum-based oil releasing agent, some of the water and the solvent may be separated to generate turbidity. As a result, the electrical resistance is also infinite. The property required for the solvent for solubilization is to dissolve water and to dissolve in low polarity petroleum release agents. Lower alcohols and glycols of C1 and C2 dissolve well in water, but are not preferred as solubilizers because they cause separation in petroleum-based oil release agents.

In addition, since an oil-based mold release agent is used while apply | coating, the toxic and low polarity solvent which has little influence on a worker's health is also a required property. In this respect, ethers and ketones which are easy to vaporize are also not preferable. Odorless properties are also important, and lower alcohols such as C3, C4 and C5 are also undesirable. Although ester has good mixing property with a low polarity type oil release agent, there exists a possibility that it may damage the health of a casting worker. In view of these points, in order to dissolve water with an oil-based release agent having a low polarity, a nonionic solubilizer having both a hydrophilic group and a lipophilic group is preferable for the present invention.

Among them, the solubilizer is most preferably a solubilizer having a HLB (Hydrophile-Lipophile Balance) range of 5 to 10. If the HLB is less than 5, water is difficult to dissolve, but easily soluble in oil. Therefore, in order to dissolve a fixed amount of water in an oil releasing agent, a large amount of solubilizer is required. If the HLB exceeds 10, it is easy to dissolve water but hard to dissolve in oil.

Thus, attempting to dissolve a certain amount of water in an oil releasing agent causes separation. As a suitable solubilizer, it is most preferable to have a suitable HLB range. As a type of emulsifier, the sorbitan type which does not raise a problem or does not cause a problem is preferable to the phenol ether type which the environmental hormone problem was often suspected.

By mixing the solubilizer, there is a fear that the original release property of the oily release agent may be inhibited and the address problem may be increased. In order to minimize these problems, it is important to keep the compounding amount of the solubilizer low. It is preferable to make the quantity of a solubilizer 9 times or less of water content.

Hereinafter, the Example of this invention is described with a comparative example.

(First embodiment)

First, the electrostatic coating device according to the first embodiment of the present invention will be described with reference to Figs. Here, FIG. 1 is an explanatory diagram of the entire schematic of the electrostatic coating device of the first embodiment, and FIG. 2 is an explanatory view showing an enlarged part of the device of the first embodiment.

The electrostatic coating device mainly includes an electrostatic coating gun 1 and an electrostatic controller 2 and a transformer 3 electrically connected to the electrostatic coating gun 1, respectively. In addition, the electrostatic coating device includes a liquid feeding device 4 for feeding an oil type lubricant to the electrostatic painting gun 1, a compressor 6 for supplying air to the electrostatic painting gun 1 through a pipe 5, A power supply (AC 200 V or 100 V) 7 for driving the electrostatic controller 2 is provided. The electrostatic imparting device 8 is configured by the electrostatic controller 2, the transformer 3, and the power source 7. The electrical signal from the transformer 3 is sent to the electrostatic spray gun 1. The oil type release agent is pressurized by the liquid pressure feeding device 4 to the electrostatic coating gun 1, mixed with air in the electrostatic coating gun 1, and misted. By interlocking the timing of the spray with the timing for imparting electrostatic, the misted oily release agent is applied to the mold in a charged state.

As the electrostatic coating gun 1, an EAB90 type manufactured by Asahi Nagasaki was used. As the electrostatic imparting device 8, a BPS210 type manufactured by Asahi Nagasaki was used. As the liquid pumping device 4, Landberg K pump (0.5 kPa) type and Oriental motor BHI62ST-18 type were used in combination.

In FIG. 2, the multi-axis robot 9 is installed in a casting machine (not shown). The electrostatic coating gun 1 is installed to the multi-axis robot 9 through the bracket 10. The oil droplet 11 charged negatively from this electrostatic spray gun 1 is sprayed onto the positively charged mold 12 and applied, as shown in FIG. The metal mold | die 12 is grounded.

As described above, the electrostatic coating device of the first embodiment includes an electrostatic imparting device 8 composed of an electrostatic controller 2, a transformer 3, and a power source 7, and an electrostatic coating gun 1 installed in the multi-axis robot 9. ) Is configured. In this configuration, since the electrostatic field is formed to return to the mold 12, the negatively charged oil droplets 11 are applied along the electrostatic field. Therefore, an oil-based mold release agent can be apply | coated uniformly also to the site | part (for example, the back surface side of a metal mold) which the electrostatic coating gun 1 does not directly face.

(Example 2 to Example 26, Comparative Example 1 to Example 19)

Below, the oil-based mold release agent for casting which concerns on this invention and a comparative example is demonstrated. In addition, in a present Example and a comparative example, the composition which solubilized water in WFR-3R which is an oil-based release agent manufactured by an inventor is demonstrated as an example.

(A) manufacturing method

First, a predetermined amount of a solubilizer is added to a heatable stainless steel kiln with a stirrer and heated to 40 ° C. Next, a predetermined amount of tap water is added and stirred for 10 minutes. Thereafter, a predetermined amount of oil-based releasing agent is added and heated to 40 ° C while stirring, followed by stirring for 10 minutes. Finally, it is confirmed that the appearance of the mixture is transparent.

(B) the composition of the sample

The sample consists of the following composition.

WFR-3R: Oil-based release agent manufactured by the applicant

Water: Tap water having a hardness of about 30 obtained from the applicant's water supply

Solubilizer: Any one of the following two types [(a) or (b)]

(a) Solubilizer of a single composition: sorbitan solubilizer (trade name: D-212) sold by Tadamoto Yushi Kabushiki Kaisha. Used in Examples 2 to 15 and Comparative Examples 1 to 11 (see Tables 3, 6 and 8 described later).

(b) Mixed type solubilizer: A mixture of alcoholic non-ion, sorbitan monorate and alkylbenzenesulfonic acid metal salt (calcium salt) of Daedomoto Yushi Co., Ltd. (trade name: Neukalgen 140). Mixed solubilizers have a higher solubilizing ability of water than single component solubilizers. It used for the 16th-26th Example and the 12th-19th comparative example of Table 4 and Table 5 mentioned later.

However, in Comparative Example 2, an electrostatic aid (BY-trade name: ES-80) was used instead of the solubilizer.

(C) Measurement of electrical resistance (according to ASTM D5682)

About 50 kW of release agent sample is taken in a 100 kW beaker, and electrical resistance is measured with the Asahisanak electrostatic tester (type EM-III). In addition, since the indicator of an electrical resistance value was unstable in the area | region where the measured value is high, the average value of 5 measurements was made into the measured value.

(D) Measurement of adhesion amount

(D-1) Preparation

The iron plate as a test piece is heated in an oven at 200 ° C for 30 minutes. Then, after standing to cool overnight with a desiccator, the mass of an iron plate is measured to 0.1 mg unit.

(D-2) Application of Oil-Based Release Agent

3 shows an application apparatus for measuring the adhesion amount. In the figure, reference numeral 21 represents a pedestal of the adhesion tester. The power supply and temperature controller 22 is provided on a part of the pedestal 21. The steel plate mount 24 incorporating the heater 23 is provided on the pedestal 21 near the power supply and temperature controller 22. The iron plate support metal member 25 is provided on one end side of the iron plate mount 24. The test piece (iron plate) 26 is arrange | positioned inside this iron plate support metal member 25. As shown in FIG. The thermocouples 27a and 27b are embedded in the vicinity of the heater 23, and the iron plate 26 and the thermocouple 27b are in contact with each other. The release agent 29 is sprayed on the iron plate 26 from the spray nozzle 28 for application.

Operation of the coating apparatus of FIG. 3 is as follows.

First, the power supply and temperature control device 22 of the coating device (manufactured by Yamaguchi Kijutsu Co., Ltd.) is set to a predetermined temperature, and the iron plate supporting metal member 25 is heated by the heater 23. Here, when the thermocouple 27a reaches the set temperature, the iron plate 26 as a test piece is placed on the iron plate supporting metal member 25, and the thermocouple 27b is brought into close contact with the iron plate 26. Thereafter, when the temperature of the iron plate 26 reaches a predetermined temperature, a predetermined amount of the release agent 29 is applied to the iron plate 26 from the spray nozzle 28. Thereafter, the iron plate 26 is taken out, cooled vertically in the air for a predetermined time, and the oil flowing vertically from the iron plate 26 is removed.

(D-3) How to measure the adhesion

The iron plate 26 on which the deposit matter is placed is placed in an oven at a predetermined temperature and for a predetermined time, then taken out and air-cooled, and left to cool with a desiccator for a predetermined time. Thereafter, the mass of the iron plate 26 with the deposit is measured to 0.1 mg unit, and the amount of deposit is calculated from the blank test and the mass change of the test piece.

(D-4) test conditions

Test conditions for Examples 2 to 15 and Comparative Examples 1 to 11 are shown in Table 1 below. In addition, although the test conditions for the 16th-26th Example and the 12th Comparative Example-19th Comparative Example shown in Table 4 and Table mentioned later are basically the same as the conditions of Table 1, air pressure: 0.05 Mpa, application amount It differs in the point of 0.3 kW. That is, the spray gun angle, application time, applied voltage, and iron plate drying conditions after the test are the same as in Table 1 below.

(E) Method of measuring friction

(E-1) Friction Test Method

4A and 4B are diagrams showing a method for measuring the frictional force of a test piece in the order of process. The operation method of the friction test is as follows. An iron plate for friction measurement (manufactured by SKD-61, 200 mm × 200 mm × 34 mm) 31 of an automatic tensile tester (trade name: Lub Tester U) manufactured by Mac International has a thermocouple 32 incorporated therein as shown in Fig. 4A. . The iron plate 31 is heated with a commercially available heater. After the instruction | command of this thermocouple 32 reaches a predetermined | prescribed, the iron plate 31 for friction measurement is erected vertically. The release agent 34 is apply | coated from the application | coating nozzle 33 on the conditions shown by the said adhesion test.

Immediately, the friction measuring iron plate 31 is placed horizontally on the tester mount 35 as shown in FIG. 4B. Further, a Mac International ring (manufactured by S45C, inner diameter 75 mm, outer diameter 100 mm, height 50 mm) 36 is placed in the center. Subsequently, 90 mol of aluminum molten metal (ADC-12, temperature 670 degreeC) 37 melt | dissolved in the ceramic melting furnace in the ring 36 is poured. Thereafter, it is left to cool for 40 seconds to solidify. Furthermore, 8.8 kg of iron pressing members (10 kg in total with molten metal) 38 were loaded on the solidified aluminum (ADC-12) immediately, and the ring 36 was tensioned while being tensioned in the arrow X direction. The frictional force of the prepared aluminum is measured.

(E-2) Friction force measurement conditions

Application conditions are the same as in Table 1. Friction force measurement conditions are shown in Table 2 below.

(F) How to measure Leidenfrost temperature

First, the iron plate used for the above-mentioned adhesion test is heated in a commercial electric furnace. Next, the surface temperature of the iron plate is measured with a non-contact thermometer. Subsequently, when the surface temperature reaches 400 ° C., the droplet of the release agent is dropped from one drop (about 0.1 kPa) pipette. Then, the situation of the droplet immediately after dropping is observed, and the following operations 1) to 3) are performed.

1) If the drop is rolling or moving, raise the surface temperature by 5 ° C and repeat the test.

2) If the droplets splash, lower the temperature by 5 ° C and repeat the test.

3) Find the boiling temperature under a relatively low movement situation between 1) and 2). This temperature is called Leidenfrost temperature.

(G) Viscosity Measurement Method

The viscosity measurement was measured based on JIS-K-2283.

(H) component and test measurement results

(H-1) Measurement Result-1: Electric Resistance

Table 3 below shows the measurement results of the composition and the electrical resistance of the second to fifth examples and the first to second comparative examples relating to the single solubilizer series. In addition, Tables 4 and 5 show the composition, adhesion, appearance, electrical resistance, 40 ° C. viscosity, and viscosity of the sixteenth to twenty-sixth and twelfth to nineteenth comparative examples of the mixed system solubilizer. The measurement result of the Leiden frost point is shown.

In Table 3, the first comparative example (water, 0 mass%), the fifth example (water, 0.2 mass%), the fourth example (water, 0.4 mass%), the third example (water, 1.0 mass% ), As shown in the second embodiment (water, 1.2 mass%), when the moisture in the oil-based release agent is increased, the battery resistance value decreases. This was the result of single solubilizer D-212, which was evaluated for mixed solubilizer Neukalgen 140 for identification.

The seventeenth example (0 mass% of water) shown in Tables 4 and 5 described above shows infinite electric resistance. On the other hand, Example 18 (0.4 mass% of water), Example 19 (1 mass% of water), Example 20 (1.2 mass% of water), Example 22 (2 mass% of water), and 23rd implementation The electrical resistance values of Examples (3 mass% of water), Example 24 (4.3 mass% of water), and Example 26 (7.5 mass% of water) were 380, 180, 115, 72, 47, 58, and 13 (MΩ), respectively. )to be. As described above, when the amount of water mixed increases, the electrical resistance value tends to decrease. In other words, increasing water together with single and mixed solubilizers tends to lower the electrical resistance.

However, slight turbidity occurs in the fourteenth comparative example (0.1% by mass of water, 0.23% by mass of solubilizer). It shows that 2.3 parts of solubilizers are needed with respect to 1 part of water. In order to mix more water than that, it is necessary to mix many solubilizers like 2nd Example, 20th Example, and 26th Example.

On the other hand, as shown in the 2nd comparative example of Table 3, since 0.3 mass% or more of electrostatic adjuvant does not melt | dissolve in an oil-based mold release agent, the electrical resistance value was measured at 0.3 mass%. However, the measurement is infinite. It is presumed that the electrostatic preparation does not dissolve so much among the oil type release agents, and thus the electrostatic effect cannot be expected as much.

In addition, Table 4 shows the adhesion amount according to the presence or absence of power failure as well as the mixing ratio of the water and the solubilizing agent which are the composition of the oil-based mold release agent for casting according to the sixteenth to twenty-sixth and the twelfth to twenty-ninth comparative examples. In addition, the amount of adhesion increase due to electrostatic discharge (lubricant component, that is, high viscosity base oil component in the oil-based release agent, three kinds of lubricant components and solubilizing agent) is also shown. In addition, Table 5 shows the appearance and condition of the casting-based oil releasing agent according to the sixteenth to twenty-sixth examples and the twelfth to twenty-ninth comparative examples of Table 4, the viscosity at 40 ° C, and the Leiden frost temperature (LF point). Indicates.

(H-2) Measurement result-2: Effect of moisture content

As described in the above (H-1), when the moisture is increased, the electrical resistance is lowered, and an electrostatic effect can be expected. However, it is necessary to draw water into the oily release agent with the help of solubilizers. However, it is necessary to optimize the amount of water and the amount of solubilizer in order to reduce the possibility of side effects to release property by water or a solubilizer.

First, the lower limit of the moisture content will be described.

In the case of using the single-component solubilizer D-212, as shown in Table 6 below, when the electrostatic coating is applied using 0.4 mass% of water of Example 4 and 0.2 mass% of water of Example 5, the adhesion amount is about 2 Mg increased. On the other hand, in the case of 0.3 mass% of the electrostatic preparations of the 2nd comparative example which does not contain water, an adhesion amount fell slightly and the electrostatic effect was not confirmed. Usually, mixing an electrostatic aid of about 0.5-1.0 mass% is recommended from the electrostatic preparation manufacturer. However, the reason why the electrostatic preparation could not be dissolved by the oil type release agent is considered to be the reason why the electrostatic effect did not appear.

In the case of using the mixture-based solubilizer Neukalgen 140, from the table 4 and the table 5, even in comparison with the twelfth comparative example without the electrostatic (water = 0, solubilizer = 0) and the thirteenth comparative example with the electrostatic There was much adhesion increase of the 13th comparative example. That is, it was confirmed that the amount of adhesion increases when there is a power failure. However, in comparison with the thirteenth comparative example (with water = 0, solubilizer = 0) and the zero water with the blackout, the increase in adhesion due to the blackout of the seventeenth embodiment including the solubilizing agent in water zero was It is about the same as 13 comparative example. In addition, in the case of the twenty-first and twenty-fifth embodiments including the solubilizing agent in the thirteenth comparative example and the zero water, the increase in adhesion due to the electrostatic discharge in the twenty-first and twenty-fifth embodiments was compared with that of the thirteenth comparative example. Many. It has also been found that polarizing solubilizers contribute to increased adhesion.

That is, when the single component solubilizer D-212 is used, the minimum of water is 0.2 mass%. On the other hand, when the mixed type solubilizer Neukalgen 140 with high solubilizing ability which is easy to adhere is used, the lower limit of water is 0 mass%. Therefore, the minimum of water can be said to be 0 mass%.

Next, the upper limit of the moisture content will be described.

In the case of using a single component solubilizer D-212, as shown in Table 3, the appearance of the third example (1.0 mass% of water) was transparent, but in the second example (1.2 mass% of water), slight turbidity was observed. And the upper limit of water was 1.2 mass%.

On the other hand, when the mixed solubilizer Neukalgen 140 is used, it can be seen in Table 20 in Example 20 (1.2 mass% of water), Example 24 (4.3 mass% of water) and Example 26 (7.5 mass% of water). As can be seen, an increase in adhesion due to power outages was seen. In addition, in the case of the sixteenth comparative example (12.9 mass% of water) and the eighteenth comparative example (21.5 mass% of water), which had a lot of moisture, the increase in adhesion due to power failure was observed, but emulsification occurred. However, in the twenty-fourth example (4.3 mass% of water) and the twenty-sixth example (7.5 mass% of water), there is no problem of emulsification, and the electrical resistance values are 58 and 13 MΩ, respectively, in a range suitable for electrostatic coating. Moreover, in Example 24 and Example 26, the viscosity in 40 degreeC was also 5.9 and 13.3 mm <2> / s, respectively, and it was confirmed that it is the property which is easy to apply | coat easily. That is, the upper limit of moisture is seen as 7.5 mass%.

Moreover, the upper limit of water is demonstrated about the practical use in casting.

If the water content is excessively increased, the performance may deteriorate in practical use. That is, when a mold release agent is apply | coated to a high temperature metal mold | die, water boils suddenly and a surface of a metal mold | die is covered with a water vapor film. As a result, the applied release agent mist becomes difficult to reach the mold surface. Therefore, the adhesion efficiency of a mold release agent falls rapidly. This is called Leidenfrost phenomenon. As shown in the eighteenth, nineteenth, twenty-second, twenty-third, twenty-fourth, and twenty-sixth embodiments of Tables 4 and 5, when the number mass% increases, The point (LF point) is clearly lowered to 440, 430, 400, 385, 375, and 365 ° C, respectively. All these examples are superior to 350 ° C. or higher which is much higher than the LF point of about 250 ° C. of the water soluble release agent. However, in some molds exceeding 400 degreeC, the problem of welding may arise. The preferable range is 2 mass% or less of water whose LF point corresponds to 400 degreeC. That is, practically, it can be said that 2 mass% or less of water is a preferable range.

(H-3) Measurement result-3: Power failure effect

As described in section (H-2), it is possible to add a lot of water, but the help of a solubilizer is required. In fact, as in the 26th embodiment of Table 4, it is possible to mix 30 mass% of the solubilizer. However, when there are many solubilizers, there is a possibility of the side effect of the increase of the address in a product. Then, the electrostatic effect at the time of apply | coating conditions was investigated using the 4th Example (1.6 mass% of solubilizer, 0.4 mass% of moisture, and 200 M (ohm) of electrical resistance value) with relatively few solubilizers. Table 7 shows the test conditions.

The results are shown in Table 8 below. Table 8 also shows the results of measurement of adhesion amount and frictional force for investigating the "effects of electrostatic power" when the test conditions (coating air pressure, coating distance, iron plate temperature, presence of power failure) were changed. In addition, the formulation of Example 6-Example 14 and Example 3-Example 11 of Table 8 is the formulation of Example 4 (that is, WFR-3R: 98.0 mass%, tap water: 0.4 mass%, soluble). Topic D-212: 1.6 mass%).

Although the amount of adhesion increase differed depending on the conditions, the amount of adhesion increased about 60% in the arithmetic mean. Clearly, the effect of electrostatic coating was confirmed. In the friction test, when it exceeds 10 kgf, welding gradually increases, and it is judged that the releasability is enough in the value below that. The effect of power failure in such a friction tester was "no difference", as shown in Table 8. In other words, although the adhesion increased, it could be said that further improvement of releasability was not seen since it was already at a sufficient friction level.

In addition, the electrostatic effect was also observed in the case of the release agent formulation of the fourth embodiment having a high level of electrical resistance of 200 MΩ. From this, it is estimated that the "optimal electrical resistance value for electrostatic coating" different from a coating material exists in a mold release agent. As can be seen in Table 4, in the case of the mixed solubilizer nukalgen 140, the sixteenth, seventeenth, eighteenth, twenty, twenty-first, and twenty-fourth embodiments In Examples 25 and 26, the amount of adhesion was higher in the case of "with power failure" than in the case of "no power failure".

(H-4) Measurement Result-4: Effect of Solubilizer

As mentioned above, even if there are too many solubilizers, it is estimated that there exists a bad influence of the mold release property during casting. Too much water cannot be drawn into the oil release agent. Again, optimization of the amount of solubilizer is required.

First, the lower limit of a solubilizer is demonstrated.

In the case of the single component solubilizer D-212, 0.2 mass% of water was transparent as shown in the fifth example (solubilizer, 0.8 mass%) of Table 3, but it was transparent, but the electrical resistance was high and unstable. Therefore, it can be inferred that this degree is a lower limit of a single component type solubilizer.

However, the lower limit is even lower for the mixed solubilizer Neukalgen 140. In Table 4 and Table 5, the sixteenth example (0.4 mass% of solubilizer and 0.1 mass% of water) is transparent. On the other hand, the external appearance of the 14th comparative example (0.23 mass% of solubilizer and 0.1 mass% of water) was cloudy, and the ability to attract water was inadequate. Therefore, it can be estimated that the lower limit of the solubilizer is about 0.3 mass%. In addition, the electric resistance value of the sixteenth embodiment is infinite. Thus, the adhesion test was conducted to confirm the electrostatic effect. The results indicate that the increase in adhesion amount is equal to 3.7 mg and 4.5 mg, which is the effect of increasing the adhesion amount of the 17th example (1 mass% solubilizer) and the 18th example (1.6 mass% solubilizer), which contains more than 4.1 mg of solubilizer. It was a level. It can be said that the electrostatic effect was confirmed also in the sixteenth embodiment having a low solubilizer level. As a result of examining both solubilizer levels of Example 17 and Example 18, the lower limit of the solubilizer was set to 0.3% by mass.

Next, the upper limit of the solubilizer will be described.

In the case of the single component solubilizer D-212, the external appearance was transparent in the third example (4.0 mass% solubilizer) in Table 3, but slightly turbid in the second example (4.8 mass% solubilizer). This vicinity can be assumed to be the upper limit concentration of the single component solubilizer.

In the case of the mixed-type solubilizer Neukalgen 140, as shown in Tables 4 and 5, the twenty-first example (5 mass% of solubilizer), the twenty-fourth example (10 mass% of solubilizer), and the 26th example ( 30 mass% of solubilizer and 7.5 mass% of water) were transparent. However, in the 16th comparative example (30 mass% of solubilizer, 12.9 mass% of water), emulsification was caused. As shown in Table 4 and Table 5, when the solubilizer increased, the electrical resistance decreased with the increase in moisture, and the adhesion amount also increased. For this reason, the upper limit of the solubilizer was set to 30%.

(H-5) Measurement Result-5: Summary

As in the twenty-first embodiment, an electrostatic effect is obtained by mixing only 5% of the solubilizer with the oil type release agent. It is not necessary to mix water. However, when water is mixed, the electrical resistance is drastically lowered, which makes it easier to apply electrostatic coating. However, in order to mix a lot of water, it is necessary to increase the solubilizer. As described above, water should be blended in the range of 0 to 7.5 mass% and solubilizer should be blended in the range of 0.3 to 30 mass%. As a result, an electrostatic effect appears, and the adhesion amount increases.

Moreover, in the concentration range other than that, the quality problem of an oil-based mold release agent arises. For example, when there is too much water, a mold release agent may emulsify and there exists a possibility of water separation. In case of oil leakage during operation, emulsifying problem is caused when emulsified release agent flows to the drain. Moreover, when emulsifying, a viscosity will become high too much and uniform spray will become difficult. Moreover, the fall of Leidenfrost temperature arises, and it is highly likely that it will become a problem of releasability by the sudden fall of adhesion amount by the dolby of water.

Too much solubilizer may cause problems in mold release properties. As the concentration of the solubilizer is increased, the adhesion amount due to the electrostatic power increases (see the 20th, 21st, 24th, 25th, 26th, and 16th comparative examples). That is, since the solubilizer which has chemical bonds, such as ester and an ether group, adsorbed to iron by the polarity much, it can be said that the amount of adhesion increased. The solubilizer is an excellent component for increasing the adhesion efficiency, but the decomposition initiation temperature is around 250 ° C., and it is easy to cause the addressing problem of the cast product. Therefore, it is important to optimize the solubilizer formulation while considering the adhesion efficiency by other lubricant components.

In addition, although the problem in an actual apparatus changes with apparatus size, operating conditions, etc., in order to suppress a problem to the minimum, it is 0.2-1.2 mass% of water and 0.8-4.8 mass% of a solubilizer.

Although not a practical practical evaluation that can be quantified, the effects of the electrostatic coating by the electrostatic coating agent provided on the multi-axis robot and the planetary release agent composition which can be electrostatically imparted to the present invention were investigated. On the condition of no electrostatic coating, the release agent of the fourth embodiment colored in red was applied. As a result, only a weak red color was seen in the inner part of the mold, and it was found that there was a part with little adhesion. On the other hand, as a result of application | coating on the condition of having electrostatic coating, it turned out that discoloration is large and the mold release agent component is abundantly attached.

In the condition of electrostatic coating, there are many adhesions in the inside of the mold or a thin part, and the effect of reducing adhesion during casting can be expected. That is, the attracting effect characteristic of electrostatic coating can be expected. It is also expected that this will lead to a reduction of the coating amount.

In the case of no electrostatic coating, the coating amount is increased in order to ensure an appropriate oil film even at a site where oil droplets are difficult to reach. In addition, excessive application | coating is carried out to the metal mold | die sited on the surface side. In the case of electrostatic coating, the application amount of this excess can be reduced. That is, electrostatic coating not only contributes to the economics of the casting manufacturer, but also contributes to the improvement of the working environment.

The oil-based lubricating release agent of the present invention is suitable for electrostatic coating when casting nonferrous metals, and is also suitable for lubrication of mold surfaces. In addition, this invention is not limited to the said embodiment as it is, In an implementation step, it can embody by changing a component within the range which does not deviate from the summary. Moreover, various inventions can be formed by appropriate combination of the some component disclosed by the said embodiment. For example, some components may be deleted from all the components shown in the embodiments. Or you may combine suitably the component over other embodiment.

Claims (5)

Distilled water, ion-exchanged water, tap water or 0 to 7.5 mass% of water which consists of 1 type, or 2 or more types chosen from the group of the water which melt | dissolved electrolyte in those water, and 0.3-30 mass% of solubilizers, It is characterized by the above-mentioned. Oil-based release agent for casting. The casting type oil release agent of Claim 1 containing 0.2-1.2 mass% of said water and 0.8-4.8 mass% of said solubilizers. Electrostatic coating using the oil-based mold release agent of Claim 1, The coating method characterized by the above-mentioned. Electrostatic coating using the oil-based mold release agent of Claim 2, The coating method characterized by the above-mentioned. An electrostatic coating device provided on an electrostatic imparting device and a multi-axis robot for electrostatic coating according to claim 3 or 4.

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